Many motorized approaches have been taken for applying additives such as nutrients and chemical modifiers, to soil for promoting growth and controlling foliage control to lawns and turf. One of the difficulties has been accurately applying such additives at high depositions rates in areas requiring clear delineation of growth. For instance, shrubbery and trees preferably have desired borders between the lawn and the surrounding mulch. If the fertilized is applied in the mulched areas, unwanted turf invasion is promoted. Similarly, in recreational areas, such as golf courses, different grasses are used for greens, fairways, approaches, and roughs. Each requires a different treatment package and application time. Application beyond the intended boundary can promote invasion of an unwanted species and a loss of the desired pattern.
While hand held spraying devices may be relatively accurately controlled, the application rate is low and labor costs are high, limiting the attractiveness in larger areas. Accordingly motorized spraying units are available for spraying larger areas, but have not overcome the problems of accurately defining the spray pattern at borders of contrasting landscape.
In one prior approach as described in U.S. Pat. No. 4,821,959 to Browning, a reservoir is mounted above and behind the operator on a riding lawn mower. An auxiliary engine operated hydraulic pump is used to disperse the additives through rearwardly disposed conduits and nozzles. With this rearward orientation of application, the operator cannot directly see the dispensing pattern and control the application of the additives to the area traversed by the mower, and must, instead, rely on the vehicle path as an approximation of the spraying pattern. A similar rear mounted spray applicator is disclosed in U.S. Pat. No. 5,553,676 to Conley.
U.S. Pat. No. 3,995,569 to Picardat discloses a riding lawn treating machine wherein liquid spray nozzles are disposed below and behind the operator. As with the above approaches, the operator is not able to see directly the spray pattern to avoid application in adjacent areas requiring different treatment protocols.
Walk behind dispensers have been proposed wherein dry granular or liquid treatment chemicals are applied within the confines of a housing located in front of the operator. U.S. Pat. No. 3,042,308 to Vicendese discloses a dispenser for feeding granular particles to a specially adapted blade of a rotary mower. U.S. Pat. No. 4,352,463 to Baker discloses a liquid treatment dispenser for spraying with a single nozzles from within a covered housing. Both applicators are manually propelled with accordingly low application rates. Also the surrounding housings preclude direct observation of the application pattern and are limited in the ability to accurately maneuver around defined areas and obstacles.
The present invention overcomes the above limitations by providing a sprayer with high maneuverability and high visibility for the purposes of edging and trimming around trees, landscaped and shrubbery areas, and areas of differing ground foliage.